new file mode 100644
--- /dev/null
+++ b/src/stream/ngx_stream_script.h
@@ -0,0 +1,123 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#ifndef _NGX_STREAM_SCRIPT_H_INCLUDED_
+#define _NGX_STREAM_SCRIPT_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_stream.h>
+
+
+typedef struct {
+    u_char                       *ip;
+    u_char                       *pos;
+    ngx_stream_variable_value_t  *sp;
+
+    ngx_str_t                     buf;
+    ngx_str_t                     line;
+
+    unsigned                      flushed:1;
+    unsigned                      skip:1;
+
+    ngx_stream_session_t         *session;
+} ngx_stream_script_engine_t;
+
+
+typedef struct {
+    ngx_conf_t                   *cf;
+    ngx_str_t                    *source;
+
+    ngx_array_t                 **flushes;
+    ngx_array_t                 **lengths;
+    ngx_array_t                 **values;
+
+    ngx_uint_t                    variables;
+    ngx_uint_t                    ncaptures;
+    ngx_uint_t                    size;
+
+    void                         *main;
+
+    unsigned                      complete_lengths:1;
+    unsigned                      complete_values:1;
+    unsigned                      zero:1;
+    unsigned                      conf_prefix:1;
+    unsigned                      root_prefix:1;
+} ngx_stream_script_compile_t;
+
+
+typedef struct {
+    ngx_str_t                     value;
+    ngx_uint_t                   *flushes;
+    void                         *lengths;
+    void                         *values;
+} ngx_stream_complex_value_t;
+
+
+typedef struct {
+    ngx_conf_t                   *cf;
+    ngx_str_t                    *value;
+    ngx_stream_complex_value_t   *complex_value;
+
+    unsigned                      zero:1;
+    unsigned                      conf_prefix:1;
+    unsigned                      root_prefix:1;
+} ngx_stream_compile_complex_value_t;
+
+
+typedef void (*ngx_stream_script_code_pt) (ngx_stream_script_engine_t *e);
+typedef size_t (*ngx_stream_script_len_code_pt) (ngx_stream_script_engine_t *e);
+
+
+typedef struct {
+    ngx_stream_script_code_pt     code;
+    uintptr_t                     len;
+} ngx_stream_script_copy_code_t;
+
+
+typedef struct {
+    ngx_stream_script_code_pt     code;
+    uintptr_t                     index;
+} ngx_stream_script_var_code_t;
+
+
+typedef struct {
+    ngx_stream_script_code_pt     code;
+    uintptr_t                     n;
+} ngx_stream_script_copy_capture_code_t;
+
+
+typedef struct {
+    ngx_stream_script_code_pt     code;
+    uintptr_t                     conf_prefix;
+} ngx_stream_script_full_name_code_t;
+
+
+void ngx_stream_script_flush_complex_value(ngx_stream_session_t *s,
+    ngx_stream_complex_value_t *val);
+ngx_int_t ngx_stream_complex_value(ngx_stream_session_t *s,
+    ngx_stream_complex_value_t *val, ngx_str_t *value);
+ngx_int_t ngx_stream_compile_complex_value(
+    ngx_stream_compile_complex_value_t *ccv);
+char *ngx_stream_set_complex_value_slot(ngx_conf_t *cf, ngx_command_t *cmd,
+    void *conf);
+
+
+ngx_uint_t ngx_stream_script_variables_count(ngx_str_t *value);
+ngx_int_t ngx_stream_script_compile(ngx_stream_script_compile_t *sc);
+
+void *ngx_stream_script_add_code(ngx_array_t *codes, size_t size, void *code);
+
+size_t ngx_stream_script_copy_len_code(ngx_stream_script_engine_t *e);
+void ngx_stream_script_copy_code(ngx_stream_script_engine_t *e);
+size_t ngx_stream_script_copy_var_len_code(ngx_stream_script_engine_t *e);
+void ngx_stream_script_copy_var_code(ngx_stream_script_engine_t *e);
+size_t ngx_stream_script_copy_capture_len_code(ngx_stream_script_engine_t *e);
+void ngx_stream_script_copy_capture_code(ngx_stream_script_engine_t *e);
+
+#endif /* _NGX_STREAM_SCRIPT_H_INCLUDED_ */